[Perf] Some optimizations

src/hooks/useShowTransition.ts

@@ -13,18 +13,18 @@ export default (
   const [isClosed, setIsClosed] = useState(!isOpen);
   const closeTimeoutRef = useRef<number>();
   // СSS class should be added in a separate tick to turn on CSS transition.
-  const [hasAsyncOpenClassName, setHasAsyncOpenClassName] = useState(false);
+  const [hasOpenClassName, setHasOpenClassName] = useState(isOpen && noOpenTransition);
 
   if (isOpen) {
     setIsClosed(false);
-    setHasAsyncOpenClassName(true);
+    setHasOpenClassName(true);
 
     if (closeTimeoutRef.current) {
       window.clearTimeout(closeTimeoutRef.current);
       closeTimeoutRef.current = undefined;
     }
   } else {
-    setHasAsyncOpenClassName(false);
+    setHasOpenClassName(false);
 
     if (!isClosed && !closeTimeoutRef.current) {
       closeTimeoutRef.current = window.setTimeout(() => {
@@ -39,7 +39,6 @@ export default (
     }
   }
 
-  const hasOpenClassName = hasAsyncOpenClassName || (isOpen && noOpenTransition);
   const isClosing = Boolean(closeTimeoutRef.current);
   const shouldRender = isOpen || isClosing;
   const transitionClassNames = buildClassName(

src/util/arePropsShallowEqual.ts

@@ -1,4 +1,8 @@
 export default function arePropsShallowEqual(currentProps: AnyLiteral, newProps: AnyLiteral) {
+  if (currentProps === newProps) {
+    return true;
+  }
+
   const currentKeys = Object.keys(currentProps);
   const currentKeysLength = currentKeys.length;
   const newKeysLength = Object.keys(newProps).length;
@@ -7,5 +11,16 @@ export default function arePropsShallowEqual(currentProps: AnyLiteral, newProps:
     return false;
   }
 
-  return currentKeys.every((prop) => currentProps[prop] === newProps[prop]);
+  if (currentKeysLength === 0) {
+    return true;
+  }
+
+  for (let i = 0; i < currentKeysLength; i++) {
+    const prop = currentKeys[i];
+    if (currentProps[prop] !== newProps[prop]) {
+      return false;
+    }
+  }
+
+  return true;
 }